1. Make sure the features are enabled
2. Go to the app-settings and add the Metadata Decorator to mark it as "Is-Shared"
3. Copy all the files from the sites App-Folder to the shared location
   1. in Dnn that's usually \Portals\_default\2sxc\[app-name]
4. Change all the mappings of the views to point to the shared location

Verify

To verify the result, rename the original app folder in the site to something else, so it cannot be used any more, and check that the output still works.